Cullinan Oncology Significantly Increases Ownership Stake in its MICA Subsidiary which Holds Worldwide Rights to Clinical-Stage Novel Monoclonal Antibody CLN-619 Cullinan increases ownership in MICA subsidiary from 54% t

Cullinan Oncology Significantly Increases Ownership Stake in its MICA Subsidiary which Holds Worldwide

Rights to Clinical-Stage Novel Monoclonal Antibody CLN-619

Cullinan increases ownership in MICA subsidiary

from 54% to 92% through share purchase from existing financial investors

The ongoing Phase I clinical trial for

CLN-619 remains on track to report initial clinical data in mid-2023

CAMBRIDGE, Mass., October 25, 2022 (GLOBE NEWSWIRE) Cullinan Oncology, Inc. (Nasdaq: CGEM), a biopharmaceutical company focused on

modality-agnostic targeted oncology, today announced that it has increased its ownership in its Cullinan MICA, Inc. (MICA) subsidiary from 54% to 92%. MICA holds the worldwide rights to CLN-619, an antibody

that restores the MICA/MICB pathway to promote tumor cell lysis from both cytotoxic innate and adaptive immune cells. CLN-619 is being investigated as both monotherapy and in combination with checkpoint

inhibitor therapy in an ongoing Phase I study in patients with advanced solid tumors. Cullinan increased its ownership by purchasing equity from two of MICA s financial investors, Avalon Ventures and Bregua Corporation, for $30.7 million.

The Myeloma Investment Fund, a venture philanthropy fund for the Multiple Myeloma Research Foundation (MMRF), maintained its ownership in the entity.

Cullinan Oncology has acquired additional ownership in the MICA subsidiary as part of our overall strategy to deploy our robust financial resources for

pipeline investment, acceleration, and expansion, said Nadim Ahmed, Chief Executive Officer of Cullinan Oncology. This investment recognizes the strategic importance of CLN-619 in our portfolio as

a key asset with first-in-class potential and strong rationale for development in a broad range of cancer indications. We are excited by the potential of this unique

approach to cancer treatment, and we remain committed to our mission to create new standards of care for patients with cancer.

hallmarks of cancer is the ability to avoid destruction by immune cells. CLN-619 is designed to overcome immune evasion by promoting NK cell-mediated tumor cell lysis and facilitating engagement of certain

classes of T-cells. This differentiated mechanism activates both the innate and adaptive immune system, providing strong rationale to target the MICA/MICB pathway as a novel approach with potential to treat

patients with cancer, said Jeff Jones, MD, MPH, MBA, Chief Medical Officer, Cullinan Oncology. Given MICA/MICB are broadly expressed across tumor types, we are committed to investigating CLN-619

across a range of malignancies, and we look forward to reporting initial clinical data from our ongoing Phase I clinical study in mid-2023.

CLN-619 is a humanized IgG1 monoclonal antibody that binds to MICA and MICB, ligands expressed on a wide variety of

hematological and solid tumors that are recognized by both cytotoxic innate and adaptive immune cells via their NKG2D receptors. To evade lysis by these immune cells, tumor cells shed MICA/MICB from their cell surface.

CLN-619 promotes an antitumor response through multiple potential mechanisms of action, including prevention of the proteolytic cleavage of MICA/MICB from cancer cells, antibody-dependent cell-mediated

cytotoxicity (ADCC), and enhancement of MICA/MICB binding to NKG2D. Multiple studies evaluating serum samples from cancer patients have demonstrated that high serum levels of shed MICA correlate with poor prognosis.

CLN-619 is being studied in an ongoing Phase I dose escalation and expansion trial both as a monotherapy and in combination with pembrolizumab. The study design allows dose level extensions as well as

expansion in tumor specific cohorts. The trial was initiated in December 2021, and initial clinical data is anticipated in mid-2023.

About Cullinan Oncology

Cullinan Oncology, Inc. (Nasdaq:

CGEM) is a biopharmaceutical company dedicated to creating new standards of care for patients with cancer. We innovate without borders to find the most promising clinic-ready cancer therapies, whether from our own discovery efforts or through

exceptional engagement with our academic and industry partners. Anchored in a deep understanding of immuno-oncology and translational cancer medicine, we leverage our scientific excellence in small molecules and biologics to create differentiated

ideas, identify unique targets, and select the optimal modality to develop transformative therapeutics across cancer indications. Powered by our novel research model, we push conventional boundaries from candidate selection to cancer therapeutic,

applying rigorous early experimentation to fast-track only the most promising assets to the clinic and ultimately commercialization. As a result, our diversified pipeline is strategically built with assets that activate the immune system or inhibit

key oncogenic drivers across a wide range of modalities, each with the potential to be the best or first in their class.

Our people possess deep

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